Unless you harbor long-term dreams of being a creepy shut-in, your house most likely has a lot of windows. Windows bring beauty and light to any house, but they come with some built-in problems. The window is the spot in your house that is most vulnerable to heat transfer, with warm air coming in during the summer or escaping during the winter. This obviously hurts your pocket, as it leads to increased energy bills. In a previous article, we discussed what is the best glass to maximize your efficiency. In this article, we’re going to look at the over-looked parts of a window: the frame. Frames are important both aesthetically and in terms of energy, but they are usually an afterthought. If you want your bills to be lowered, though, you’re going to have to put them on equal footing. Here is what you should look for in energy-efficient frames.

AL VALUE

When discussing glass, we mentioned the R-Value an U-Factor. Those are not complicated, but they look like advanced calculus compared to AL Value, thankfully. AL Value is Air Leakage, and, clearly, you want a frame with the lowest value. Neutralizing for material, frames have to be tight and barely permeable against the window. AL, measured in cubic feet per minute per square foot, measures how much air is escaping. The highest quality window has an AL of .01. You want the lowest value, with zero being impossible. So what will give you the lowest?

FIXED WINDOWS

It isn’t just the material that matters; it is the way the frame interacts with the window. There are some windows that are designed not to open. They are sealed against the frame, and this allows for a very small AL Value. Obviously, you don’t want every window, or even most in your house to be fixed, but having a few that are allows your house to be more efficient without distracting from your comfort or aesthetic standards.

ALUMINUM FRAMES

Aluminum frames are cheap, durable, low-maintenance, and about as bad in terms of AL Value as you can get. These are extremely permeable and allow air to flow in and out as if they weren’t there. They absorb and transfer both heat and cold. And as anyone who has seen aluminum in the winter knows, they are magnets for condensation.

WOOD FRAMES

Wood frames are sturdy and extremely pleasing to the eye, considerably more so than aluminum. The big problem with wood frames is upkeep- they obviously require a lot, mostly in terms of keeping the clean, but also making sure they aren’t absorbing moisture. The hidden benefit of wood is that it is excellent at preventing air transfer, making it extremely energy-efficient.

VINYL AND FIBERGLASS FRAMES

Vinyl is one of the best materials there is for enhancing your energy-efficiency. Vinyl is cheap, durable and requires almost no maintenance, and generally has an excellent AL Value. Its big problem is that it can be kind of ugly. Fiberglass frames provide all the benefit of vinyl, being even sturdier and just as highly (or lowly) rated in terms of AL, but are also pleasing to the eye. They are considerably more expensive, though, so you have to balance your priorities.

We never think about frames, but they are important. In the art world, a good frame can make the price of a painting soar exponentially. In home-building, a bad frame can do the same to your heating bill. Don’t let a bad frame hurt your wallet. Whatever you choose, remember that certified window contractors can frame your solution in the best possible way.